Elevator for pipes



|NVENTOR ATORNEY.

A. L.. STONE ELEVATOR FOR PIPES F'lled Feb lO, 1947 L VV Patented Feb. 7, 1950 alveo STATE T OFFICE 2,496,360 ELEvA'roR Foa Piras poration of Delaware Application February 10, 194i', Serial No. 727,712

(Cl. V29am-96) A 5 Claims. 1

The present invention is directed to a device adapted to engage with a tubular structure for grasping the structure and moving it from one position to the other. More particularly, the present invention is directed to an elevator suitable for handling drill pipe in a derrick.

When moving a vertical or substantially vertical tubular structure member from one position to another it is often desirable to provide a means or elevator for engaging with the tubular member whereby power may be 'applied through the engaging means to aid or cause the tubular member to be moved from one position to another'. An example of such an operation is the handling of stands of drill pipe in a derrick during operation of drilling the borehole. In such operation a derrcl; is mounted on the site of the borehole and is provided with hoistingl mechanism. Conventionally the hoisting mechanism employed includes a crown block, a traveling block suspended from the crown block, a drilling line having one end secured to a hoisting drum and suspending the traveling block from the crown block, a hook carried by the traveling block and an elevator suspended from the hook for engaging and disengaging with the end of a joint of drill pipe. It is usual to provide an end of each joint of drill pipe with an external shoulder, as by forming a shoulder on the tool joint secured to an end of the joint of pipe. adapted to cooperate with the elevator. However, under some circumstances it is desirable to use so-called external flush drill pipe or slim hole pipe and when em ploying such pipe it is necessary to use an elevator plug which screws into the upper end of the f pipe and denes a shoulder which will engage with the external elevators conventionally employed.

Conventional elevators arranged to engage with the shoulder 'clened by the tool joint of drill pipe or `an elevator plug screwed into the upper end of the length of pipe to be handled offer disadvantages well known to the art. These elevators must be manually engaged with and disengaged from the drill pipe being handled. In addition, the arrangement of an external shoulder to engage with `the elevator presents dculties. In the interest of economics as well as good structural design, it Vis not desirable to provide tool joints with external shoulders. Elevator plugs are unsatisfactory because of the time elei ment involved in screwing and unscrewing the plugs inthe joint or pipe being handled, and in addition, the use of these plugs introduces an additional hazard in the handling of the drill i devise an elevator arranged to engage releasably with the interior threads of a .joint of pipe.

A further object of the present invention is to devise an elevator having an expandable mandril which is adapted to engage with the interior Tjthreads of a joint of .pipe for suspending the pipe or drill string with means provided for insuring against the release of the elevator while a load is suspended therefrom.

A still further object of the present invention is to provide an elevator adapted for handling drill pipe which engages with the interior threads oi a stand of the pipe and supports the weight from` the threads and which automatically locks or latches to the stand of drill pipe to be suspended and which is readily releasable therefrom.

Other objects and advantages of the present invention may b'e seen from the following description taken in conjunction with the drawings, in which:

Fig. 1 is an elevation, partly in section, showing an embodiment of the present invention with the parts in position for engaging with a stand of P1135;

Fig. 2 is an elevation, partly in section, of the embodiment of Fig. l with the device engaged with a stand of pipe showing the positions assumed by the various parts;

Fig. 3 is an elevation of a portion of Fig. l;

Fig. 4 is a top view of Fig. 3.

For convenience the device shown in the drawings has the principal parts or assemblies designated by letters and component parts of the assemblies or portions of a principal part desig nated by numerals.

The device of the drawing includes as principal parts and assemblies mandril A, expander B, piston C, power spring D, body assembly F, trigger assembly G, outside tube H and reservoir member J.

The mandril A is adapted to assume an expanded state and a contracted state. In Fig. l the mandril A is shown in its contracted state and in Fig. 2 the mandril is shown in its expanded stateltoengage with the interior screw threads of a tool joint box. Expander 1 3 is arranged to assume a rst position which allows the mandril to assume its contracted state; the expander in its rst position is shown in Fig. 1. The expander is slidably movable from its rst to its second position and when moved to its second position causes the mandrl to assume its expanded state; the expander is shown in its second position in Fig. 2. Power spring D biases expander B to its second position.

Trigger' assembly G cooperates with expander B to retain it in its rst position. In Fig. 1 the trigger assembly maintains the expander B in its first position against the bias exerted by power spring D while in Fig. 2 the trigger mechanism has been released allowing expander B to move to its second position and expand mandril A.

The body assembly F provides the mounting means for mandril A, expander B, piston C, power spring D and trigger assembly G. In addition, the body assernoly'e1 cooperates with outside tube' H, reservoir member J and piston C to denne a hydraulic system. The hydraulic system insures that a positive fiuid pressure will be exerted upon the upper surface of piston C when suspending force pulls outside tube H upwardly; this pressure exerted on spring C supplements the force exerted by piston C and biases expander B to its second position; in the design oi' the complete assembly spring D and the hydraulic system are each designed to exert separately a suicient force to bias expander B to its second position insuring that the mandril A will be maintained in its expanded position when the elevator is carrying a load.

In order to move expander B from its second position to its rst position against the bias of spring D or against the bias of spring D and hydraulic pressure a means is provided for exerting pressure against the underside of piston C. In Fig. l means for supplying such a pressure is shown as an air hose in cooperation with the elevator and is designated as assembly K.

'lll e construction of the device shown in the drawing wili now be described in detail.

body assembly F includes a member ll having its upper end defining a generally tubular shape, the lower portion of which is provided with a wall or partition i2 which denes a passage for receivinfr expander B and a port i3 for cooperating with the releasing assembly K. The upper end oi' body l i defines an exterior shoulder or head ifi which is provided with seals I5 and immediately below which is a radially extending port it. rEhe lower end oi member Il defines screw threads.

in addition to member il, the body assembly F includes a shoulder ring il removably secured to the iower end of member il by suitable screw threads. Shoulder ring il serves as the attaching means for securing mandril A and trigger assembly G to the body assembly F. Shoulder ring also serves as the mounting means for funnel member i8 which aids in guiding the mandril into position to engage with a joint of pipe.

Mounted on member i l immediately above and retained in position by the shoulder ring is a ring it which serves as a stop to limit the downward movement of outside tube H.

Mandril A consists of a plurality of sections or jaws 2e which are secured together as by being vulcanized to rubber 2i. Each member 20 defines an outer extending annular shoulder 22 which cooperates with shoulder 23 defined by shoulder ring il to maintain the mandril in xed position with respect to body assembly F. Each member 2d carries a centering stop pin 24 and has drilled therethrough a longitudinally extending passage 2E. The several members 20 with the rubber bonding material 2i denne an axial tapered passage 2E for cooperating with expander B and exterior screw threads 2l for cooperating with the tool joint box with which the device is adapted to be engaged.

Expander B defines an upper portion 30 of a cylindrical configuration with the exception of a shoulder or boss 3i and a circular groove 32. rihe lower portion of expander B denes a tapered surface Piston C is secured to the upper end of expander B by nut 35 with the lower surface of the piston resting on boss 3l. To the lower end of expander B is secured a guide cone 36 by any suitable means such as pin 31.

Trigger assembly G includes trigger pins 40 each of which is arranged in an opening 25 defined by mancril A, trigger pin springs 4l with each spring arranged about a pin 40 to bias it downwardly, lower trigger ring 42, upper trigger ring 533, spring 45 and balls 45. The lower portion of body member il denes a downwardly extending inner ring :15 having openings 41 receiving balls 45 and a downwardly extending outer ring d within which is arranged upper trigger ring 43.

The upper portionof upper trigger ring 43 dennes an inwardly extending circular shoulder 68, for convenience, termed a small annulus which is connected by a tapering shoulder with annulus 5B, hereafter referred to for convenience as large annulus. Trigger pin springs 4| are arranged to bias the trigger pins downwardly and, similarly, spring d4 is arranged to bias upper trigger ring 33 downwardly. if expander B is in its upper position and lower trigger ring 42 is free to assume its lowermost position under the bias exerted by springs 4l and 4d, the upper trigger ring 43 is moved downwardly to bring the surface defining small annulus 48 into contact with balls i5 thereby forcing the balls into groove 32 and locking expander B against longitudinal movement. The trigger assembly G releases expander B yfor longitudinal movement when lower trigger ring 42 is forced upwardly in the following manner. The movement of lower trigger ring [i2 upwardly in turn forces trigger pins te upwardly which in turn move upper ring 43 upwardly, this moves the small annulus 48 out of contact with balls 45 and brings large annulus 5G adjacent the balls. When the small annulus is moved out of contact with the balls they are no longer restrained within groove and expander B is released to move longitudinally. It will be noted that reservoir member J is fixedl in position with respect to member ii of body assembly F with the lower end of member J setting on ashoulder dened by member il and the upper portion secured to member li by means oi a plate 'H secured to member il by cap screws lf2. Y

The hydraulic system of the device includes a reservoir 63 dened by the interior surfaces of reservoir member J, an annulus 54 which is dened by the exterior wall of reservoir member J and a portion of the interior wall of member ll, an annulus 65 which is defined by the exterior wall of member l and the interior wall of tube H and space 5% which is within member il and bounded by the upper surface of piston C and the lower surface of member J.

It will be noted that annulus is variable in aisance s volume depending on the position of tube H with respect to assembly F. When the tube H is in its lowermost position, the volume of annulus 65 is at its maximum and when tube H is in its uppermost position, the volume of annulus 65 is substantially zero. Space SI is also variable in volume depending upon the position of piston C.

Communication between annulus 65 and annulus 6e is provided by port I6. Communication between annulus lidand space It is provided by passage 5l controlled by check valve E8. Cornm'unication between reservoir 63 and annulus 64 is provided by passage 59 controlled by Vcheck valve 1D. Pressure relief valve 62 allows fluid to pass from space 66 to space G3 when the pressure in space 65 exceeds that at which the pressure relief valve is adjusted to operate. Space S3 may be at atmospheric pressure, as indicated by vent I3 in plate 1I.

The hydraulic system is arranged so that a positive fluid pressure will be exerted on the upper surface of piston C when outside tube H is pulled upwardly with respect to body assembly F. If it be assumed that outside tube H is in its uppermost position with respect to body assembly F and is moved downwardly, the pressure inrannulus G5 is lower than that in annulus 54 and uid, therefore. passes from reservoir space E3 through passage 69 into annulus 64 and thence through port IE into space B5. This allows tube H to move downwardly with respect to body assembly F with little restraint to the hydraulic system; however, when tube H is withdrawn upwardly with respect to body assembly F, check valve 'lll prevents passage of duid from annulus 5l! into space 63 while check valve oli allows fluid to pass from annulus 64 into space E5 thereby causing a positive 'ui'cl pressure to be exerted on the 'upper surface of piston C. When outside tube H is forced upwardly and the hydraulic pressure in space 66 becomes greater than the predetermined value, the excess pressure may be relieved with uid passing from space 65 to reservoir 63 through pressure relief valve 62; this allows tube H to move upwardly until shoulder 'M thereof contacts shoulder I l! of member II.

From the detailed description of the apparatus as given above. the operation of the devlcewill be apparent. When using the device as an elevator in a conventional drilling rig, it will be supported from the hook of the travelling block by becket 14. If it is desired to attach the elevator to a stand of drill pipe, the parts of the device will be in the position shown in Fig. 1. The `device will then be lowered until lower trigger ring 42 contacts the upper vsurface of the tool joint box to be engaged and the remainder of the device continues to move downwardly, whereupon the trigger assembly G releases expander B which is then forced downwardly by power spring D to expand the mandril A to the position shown in Fig. 2. Body assembly F is stopped by a contact between trigger assembly G with the upper end of the tool joint to be engaged but outside tube H is free to slide downwardly until it contacts stop ring Ill. This lost motion incorporated into the device corresponds to the action of conventional elevators slipping down the pipe after latching and gives the driller an opportunity to stop the movement of the travelling block after the elevator latches and before the travelling block strikes the elevator assembly.

Because of the bias exerted by power spring D, mandril A is expanded almost immediately after lower trigger ring #.2 is rnoved upwardly to r lease the trigger assembly G. This stops 'the downward movement of body assembly F but the driller is provided with an opportunity for stop ping the travelling blocks without danger of the heavy block striking the upper end of the asseme bly by the distance equal to that which tube J may travel from its upper position in contact with its shoulder' I E `to its lower position in contact with stop ring IIJ of assembly F.

Power spring D exerts a bias against expander B sufliciently great to maintain the screw threads 0f mandril A engaged with the screwthreads of drill pipe being picked up by the assembly. However, as a safety measure, the load is placed on the device b-y movement upwardly of the travelling block outside and tube H is forced upwardly to increase the hydraulic pressure in space which in turn is transmitted to Space 6B and exerted against the upper surface of piston C. Accordingly, in normal operation under load, expander B is held in the position by the bi'as exerted by power spring D plus the bias exerted on the piston C by the hydraulic system.

After the device has been engaged, as shown in Fig. 2, it may be disengaged by attaching an air hose to port I3 and exerting 'a pressure 'against the lower surface of piston C suliiciently great to overcome the bias of power spring D and the pressure of the iiuid in space 5S whereby the piston is forced upwardly and the excess iiuld discharged from space tt through pressure relief Valve 62 into reservoir 63.

As heretofore explained, the expansion of mandril A by expander E requires longitudinal movement of piston C' which, in turn, alters the volume of space et. When piston C moves downwardly the voluzne'or space E6 is increased in size; liquid is thereupon drawn into space ES with the fluid passing from annulus d through pas'- sage 5l; it will be evident under these cir-cronu stances that iiuid may pass into annulus ad either from reservoir 63 or from space E5. tlowever, when releasing the device and piston C is moved upwardly as is necessary for contraction of mandril l the fluid cannot pass from space $6 into annulus Sli because passage et is con*A trolle'd by check valve d3; accordingly, sufficient pressure must be exerted on the lunderside or piston C to lforce fluid from space 1% through pressure release valve di. into space S3. As hereL tofore explained, the piston C is moved upwardly to allow xnandril A to contract by attaching an air hose K which is iiuidly connected to a suitable source of compressed air, not shown, to port I3 and pressure is exerted by the compressed air against the lower surface or piston C.

The elevator described heretofore will be seen to have a number of advantages. One of the advantages is that the expanding member B is locked by trigger assembly G in its up position and cannot be released until the trigger ring 32 strikes the top of the tool joint box. The power spring .D 'moves the expander down at a much greater speed than the elevator is travelling to set the jaws ci mandril A at the correct diameter. Expander B has a locking taper so that the force exerted inwardly against it by mandril A will not cause it to raise, which action would release the mandril.

With regard to the threads of mandril A and the threads of the tool joint box, it will be seen that if the threads vor the two members Iare apart with the two cones at the correct depth the crests of the threads will .une up and prevent both expansion of the jaws and downward movement of the mandrll. However, even though the crests of the threads do line up with the two threaded members 180 apart, the threads of the mandril will make a final seat when the elevator is started up. If the threads of the two members are less than 180 apart on a new flat top thread, the crests will pass and the 60 angle conventionally used for the threads will pull the two members together and even if the crests of the threads strike, the downward motion of the elevator will push lthe mandril past so that the next thread will be engaged. The over travel of expander B may be great enoughto makeagood iit in the threads in the next or even several threads above that at which the mandril is stopped by contact of the crest of the thread of the mandrl with the crest of the thread of the tool joint box. In any case the threads of the tool joint box will not be damaged any more by the elevator than in the conventional handling of the pipe because the expanding force of the mandril urged by the spring will not exert as much damaging force to the crests as they suier during conventional stabbing and spinning operations.

As heretofore pointed out, the mandril A is expanded into the tool joint box. rIhis has an advantage over the conventional elevator plug in that the jaws can be made tight enough to prevent loosening of the elevator while rotating the joint of pipe. However, the pressure exerted by the mandril on the tool joint box need not be so great as to damage the box because by suitably proportioning the size of the component parts of the device any desired outward force may be exerted, and this force may be made equal to that present in a conventional screwed up joint.

It has heretofore been pointed out that power spring D may be designed to exert a sufficient force to hold the elevator engaged with pipe under full load. However, as a safety measure the hydraulic system is employed whereby as load is applied to elevator, outside tube H moves upwardly which causes a predetermined hydraulic pressure to be exerted on the top of piston C which in turn is transmitted to expander B. The only outside source oi power used for manipulating the elevator is the source of compressed air applied through airhose K. If this line should accidentally become cut it will not cause premature release of the elevator but will prevent release of the elevator.

In the embodiment shown in the drawing, the mandril A may be readily replaced by mandril of a diierent size whereby the elevator may be conveniently used with different sizes of pipe. In order to change a Ina-ndril the guide cone 35 is first removed by compressing snap ring 3T. A shoulder ring Il is unscrewed from body Il and removed with mandril A, lower trigger ring 42, locking pin 24, trigger pins it and springs 25. The parts A, E2, 24, 40 and 25 remain together as a unit and may be replaced by another assembly of another size but having similar parts. rihe shoulder ring il may be used with all sizes of mandril assemblies.

When stabbing the elevator into a tool joint box, the expander B will be in its up position with guide cone 37 in contact with the lower portion of mandril A; the guide cone and the tapering outer surface of mandril A making a double angle cone which is free to pass to the bottom of the box thread. The guide funnel le need not be a close nt on the outside of the tool joint box. For example, with a Ill/z inch tool joint box, the elevator can be swinging in atl/2 inch circle or L.i1/2 inches ofi center and the funnel will strike the tool joint box and guide it until cone guide Se enters the tool joint box.

While I have disclosed specific embodiments of the present invention, it will be evident to a workman skilled in the art that various changes in the size, shape and proportions of the parts of the combination may be made without de-V parting from the scope of the invention.

Having fully described and illustrated a preferred embodiment of the present invention, what I desire to claim as new and useful and to secure by Letters Patent is:

l. A pipe elevator comprising in combination a body, a mandril mounted on said body and arranged to assume an expanded state and a contracted state, a tapered member carried by the mandril slidably movable from a first to a second position and forcing the mandril from its contracted to its expanded state as said tapered member moves from its rst to its second position, means carried by the body arranged for moving said tapered member from its first to its second position, trigger mechanism includa contact member carried by the body ar ranged to lock the tapered member in its first position when the Contact member is in a first position and to release said tapered member when the lconta ct member is in a second position, said contact i. rwiber being arranged to be moved from its n t to its second position upon contacting the pipe to be engaged by the elevator.

2. An elevator for handling pipe comprising in combinail` c. a body, a mandril mounted on said body and arranged to assume a contracted state and an expanded state, expanding member slidably carried by the mandril and Yadapted to assume a first position when the man dril is in its contracted state and movable to a second position to force the mandril into its expanded state, a piston mounted on an expending member and arranged to cooperate with a portion of the body to define a reservoir, fluid arranged in reservoir in contact with said piston and a slidable member mounted on the body adapted to be moved from a first to a sec ond position and means cooperating with the body arranged to increase the pressure exerted on the piston by the iluid in said reservoir as the slidable member is moved from its first to its second position.

3. A pipe elevator adapted to engage with the screw thread deiined by a tubular member comn prising, in combination, a body, a chuck assembly carried by the body comprising a mounting means, a plurality of gripping members each definingan irregular surface adapted to engage with a portionrof said screw thread, said members being carried by the mounting means and arranged to assume a rst position with the irregular surfaces of each gripping member out of contact with said screw thread. and movable to a second position ivth the irregular surface of each gripping member engaged with said screw thread, a slidable memberin contact with each of said gripping members and movable from a first to a second position and arranged to move each gripping member from its rst to its second position upon movement from its rst to its second position, a trigger mechanism including a Contact member carried by the body arranged tovlock said slidable member in its rst position 'when the contact member is in a first position and to release the slidable member for movement from its rst to its second position when the contact member is in a second position, said contact member being arranged to be moved from its iirst to a second position upon contacting the pipe to be engaged by the elevator.

4. A device in accordance with claim 3 in which means is arranged to bias said slidable member from its rst to its second position.

5. A pipe elevator adapted to engage releasably with the screw thread defined by a tubular member comprising, in combination, a body arranged to be suspended in a derrick, a chuck assembly carried by the body and comprising a mounting means, a plurality of gripping members each defining an irregular surface adapted to engage with a portion of said screw thread, said members being carried by the mounting means and arranged to assume a first position with the irregular surfaces of each gripping member out of contact with said screw thread and movable to a second position with the irregular surface of each gripping member engaged with said screw thread, an activating member slidably mounted on the body arranged to move from a rst to a second position and upon such movement to move the gripping members simultaneously from their first to their second positions, a trigger mechanism including a activating member from its rst to its second position, and a piston carried on the activating member and slidably arranged in the body to cooperate with the body to dene two chambers of variable capacity.

ALBERT L. STONE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,752,656 Spang Apr., 1, 1930 2,263,758 Brown Nov. 25, 1941 FOREIGN PATENTS Number Country Date 5,162 Austria 1901 

